1. Field of the Invention
The present invention relates to a ferroelectric information storage device, and more particularly, to a ferroelectric information storage device, using a conductive roller and methods of writing/reading information to/from the ferroelectric information storage device. More particularly the conductive roller could be nano-sized.
2. Description of the Related Art
A conventional probe-type ferroelectric information storage device uses a probe that is used in a scanning tunneling microscope (STM), an atomic force microscope (AFM), or a scanning probe microscope (SPM). The probe forms an electric field in a ferroelectric film to control the direction of polarization in the ferroelectric film (See U.S. Pat. No. 6,854,648).
A conventional information storage device using a probe typically includes a recording medium having a ferroelectric layer. A probe that records/reproduces information to/from the recording medium is in a state that it contacts or does not contact the recording medium. A scanner operates the probe. The scanner includes a cantilever supporting the probe and a Micro Electro Mechanical Systems (MEMS) actuator operating the cantilever.
The conventional information storage device including the probe and the scanner operating the probe has a complicated structure, resulting in high manufacturing cost. In particular, when information is recorded/reproduced in a state that the probe contacts the recording medium, the probe and the recording medium suffer from wear and tear.
When information is recorded and reproduced in a state that the probe does not contact the recording medium, a control unit is required to maintain a constant distance between the probe and the recording medium. Due to the use of the control unit, the information storage device suffers high manufacturing costs and becomes bulky.